Vector-borne infections are persistent public health threats worldwide. In recent years, a number of mosquito-borne viruses have emerged or re-emerged to cause major disease outbreaks. Other vector-borne pathogens, however, remain understudied and much neglected especially in the developing regions of the world including Southeast Asia. In this study, the brown dog tick Rhipicephalus sanguineus sensu lato, cat louse Felicola subrostratus, and cat fleas Ctenocephalides felis and Ctenocephalides orientis collected from free-ranging cats and dogs in Malaysia were molecularly screened for the presence of Bartonella and Rickettsia bacteria, and Dipylidium tapeworm. Our results showed the presence of Bartonella clarridgeiea, Bartonella henselae (lineage Marseille and lineage Houston-1), and Rickettsia sp. in C. felis. We also detected Rickettsia asembonensis in C. orientis and R. sanguineus s.l. Additionally, this study provides the first documentation on a potentially new species of Dipylidium infecting F. subrostratus and C. felis. Our results highlight the role of ectoparasites from free-ranging animals including cats and dogs, in harboring multiple transmissible pathogens.
Rickettsioses and bartonelloses are arthropod-borne diseases of mammals with widespread geographical distributions. Yet their occurrence in specific regions, their association with different vectors and hosts and the infection rate of arthropod-vectors with these agents remain poorly studied in South-east Asia. We conducted entomological field surveys in the Lao PDR (Laos) and Borneo, Malaysia by surveying fleas, ticks, and lice from domestic dogs and collected additional samples from domestic cows and pigs in Laos. Rickettsia felis was detected by real-time PCR with similar overall flea infection rate in Laos (76.6%, 69/90) and Borneo (74.4%, 268/360). Both of the encountered flea vectors Ctenocephalides orientis and Ctenocephalides felis felis were infected with R. felis. The degrees of similarity of partial gltA and ompA genes with recognized species indicate the rickettsia detected in two Boophilus spp. ticks collected from a cow in Laos may be a new species. Isolation and further characterization will be necessary to specify it as a new species. Bartonella clarridgeiae was detected in 3/90 (3.3%) and 2/360 (0.6%) of examined fleas from Laos and Borneo, respectively. Two fleas collected in Laos and one flea collected in Borneo were co-infected with both R. felis and B. clarridgeiae. Further investigations are needed in order to isolate these agents and to determine their epidemiology and aetiological role in unknown fever in patients from these areas.